The growing importance of alternative energy sources has brought a renewed interest in the Fischer-Tropsch synthesis as one of the more attractive direct and environmentally acceptable paths to high quality transportation fuels. The Fischer-Tropsch synthesis involves the production of hydrocarbons by the catalyzed reaction of CO and hydrogen. Commercial plants have operated in Germany, South Africa and other parts of the world based on the use of particular catalysts. The German commercial operation, for example, concentrated on the use of a precipitated cobalt-thoria-kieselguhr fixed-bed catalyst, and a later modification where MgO, for economy reasons, replaced part of the thoria.
More recently, U.S. Pat. No. 4,088,671 to T. P. Kobylinski describes the use of a ruthenium promoted cobalt catalyst on a support, such as alumina or kieselguhr, in the synthesis of hydrocarbons from the reaction of CO and hydrogen at substantially atmospheric pressure. It was found that the addition of small amounts of ruthenium to a cobalt synthesis catalyst resulted in the substantial elimination of methane from the product, together with the production of a more saturated, higher average carbon number product. Likewise, catalyst comprising cobalt-thoria-MgO on an alumina or kieselguhr support is described in British Pat. No. 1,548,468 to Bijwaard et al for use in the Fischer-Tropsch synthesis of hydrocarbons. Aqueous solutions of metal salts were used to impregnate the support to prepare the catalyst in the aforesaid processes, and the particular nature of the support was not seen as critical.